The present invention relates to methods of reverse engineering gas turbine engine components, and more particularly to reverse engineering gas turbine engine components having blade root attachment features.
Over the life of a gas turbine engine, numerous engine components will become worn or damaged and require repair or replacement. This is particularly true for so-called life-limited parts. In some situations, wear or damage to a particular component may be beyond repairable limits, making replacement necessary. This is frequently the case for turbine blades and rotor disks to which those blades are secured.
In situations where original design specifications or blueprints are unavailable, it is necessary to reverse engineer existing components in order to fabricate replacement components. The reverse engineering of gas turbine engine components such as turbine blades and rotor disks presents a number of unique problems. For example, turbine blades typically include a shaped root portion (e.g., a firtree, dovetail, or otherwise shaped root) that is secured within a correspondingly shaped slot in a rim of a rotor disk, and these features can be collectively referred to as root attachment features. These root attachment features provide precise engagement surfaces and shapes, and the tolerances of such features can be difficult to determine. Moreover, gas turbine engine components are often extremely expensive to purchase or fabricate, which limits the number of parts that can be analyzed for comparative purposes during reverse engineering. In addition, gas turbine engine components for aerospace applications are generally subject to stringent government regulation, placing great demands on reverse engineering processes to produce replacement components that satisfy the applicable laws and regulations in order to obtain approval for use in service.